1. Field of the Invention
The present invention relates to a parallax correcting apparatus for a real image type of viewfinder which may be incorporated in a lens-shutter type of camera.
2. Description of Related Art
Some viewfinders, of conventional real image type, incorporated in cameras are provided with an erecting optical system including a roof mirror which is positioned between the objective optical system and the eyepiece optical system in an optical path of the viewfinder. The roof mirror has a pair of reflecting surfaces which are perpendicular to one another. The roof mirror has the same function as a roof prism. The degree of parallax in a viewfinder, with respect to a photographing optical system, varies depending upon the position where the roof mirror is fixed. Therefore, the roof mirror is normally designed to be fixed in a position within the viewfinder in order to minimize parallax.
In the conventional manufacturing process for a viewfinder, the roof mirror is not precisely fixed in a predetermined position where parallax is minimal since fixing the roof mirror in an exact position where parallax is minimized, in practice, quite difficult. For this reason, it cannot be said, for a conventional camera having a real image type of viewfinder, that parallax is rendered sufficiently small.